The present invention relates to nonseparable thrust ball bearings for use in pipe joints and the like.
Nonseparable thrust ball bearings are used in pipe joints to achieve an improved work efficiency by eliminating conjoint rotation of the two joint members and reducing the fastening torque, and to prevent defacement of the gasket to be interposed between the two joint members.
Such thrust ball bearings already known include those comprising a pair of races spaced apart in the direction of axis of rotation, a plurality of balls rollable between the two races, and a connecting ring rotatably connecting the two races together. The ring is provided at its respective ends with tapered retaining portions engaging with tapered faces of the respective races for preventing slipping off (see Unexamined Japanese Utility Model Publication SHO 63-177380).
With the conventional nonseparable thrust ball bearing described, each tapered retaining portion of the connecting ring is in engagement with the race, so that the ring is connected to the race by a portion of diminished area. This involves the following problem.
When the balls are to be held between the two races reliably, the retaining portions of the ring need to be firmly held pressed against the races, consequently impeding smooth rotation. Conversely, if it is attempted to obviate the objection and ensure smooth rotation, the races are liable to separate from the balls because the connection between the retaining portion of the connecting ring and the race is diminished.